Bsi bs en 01673 2000 + a1 2009

EUROPÄISCHE NORM December 2009 English Version Food processing machinery - Rotary rack ovens - Safety and hygiene requirements Machines pour les produits alimentaires - Fours à chariot

This British Standard is the UK implementation of EN 1673:2000+A1:2009

It supersedes BS EN 1673:2000 which is withdrawn

The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CEN text carry the number of the CEN amendment For example, text altered by CEN amendment A1 is

indicated by !"

The UK participation in its preparation was entrusted by Technical Committee MCE/3, Safeguarding of machinery, to Subcommittee MCE/3/5, Food industry machines

A list of organizations represented on this subcommittee can be obtained on request to its secretary

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard cannot confer immunity from legal obligations

This British Standard, having

been prepared under the

direction of the Engineering

Sector Committee, was

published under the authority

of the Standards Committee

and comes into effect on

EUROPÄISCHE NORM December 2009

English Version Food processing machinery - Rotary rack ovens - Safety and

hygiene requirements

Machines pour les produits alimentaires - Fours à chariot

rotatif - Prescriptions relatives à la sécurité et l'hygiène

Nahrungsmittelmaschinen - Stikken-Backöfen - Sicherheits- und Hygieneanforderungen

This European Standard was approved by CEN on 11 June 2000 and includes Amendment 1 approved by CEN on 24 October 2009 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E FÜ R N O R M U N G

Contents Page

Foreword 3

Introduction 3

1 Scope 3

2 Normative references 4

3 Description 5

4 !List of significant hazards"" 7

4.2 Mechanical hazards 7

4.3 Electrical hazards 8

4.4 Thermal hazards 8

4.5 Explosion and fire hazards 8

4.6 Hazard from being trapped inside 8

4.7 Hazard generated by neglecting hygienic design principles 8

4.8 Hazards generated by neglecting ergonomic principles 8

5 !Safety and hygiene requirements and/or protective measures"" 8

5.2 Mechanical hazards 9

5.3 !Electrical hazards"" 11

5.4 Thermal hazards 12

5.5 Fire hazards due to overheating 13

5.6 Hazard from being trapped inside 13

5.7 Hygiene requirements 13

5.8 Hazards generated by neglecting ergonomic principles 14

6 Verification of the safety and hygiene requirements and/or measures 14

7 Information for use 15

Annex A (normative) Principles of design to ensure the cleanability of rotary rack ovens 17

A.1 !Terms and definitions"" 17

A.2 Materials of construction 17

A.3 Design 18

Annex B (normative) Noise test code - Grade 2 of accuracy 35

B.1 !Terms and definitions"" 35

B.2 Installation and mounting conditions 35

B.3 Operating conditions 35

B.4 Measurements 35

B.5 Emission sound pressure level determination 35

B.6 Sound power level determination 36

B.7 Measurement uncertainties 36

B.8 Information to be recorded 36

B.9 Information to be reported 36

B.10 Declaration and verification of noise emission values 37

Annex ZA (informative) !!Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC"" 39

Foreword

This document (EN 1673:2000+A1:2009) has been prepared by Technical Committee CEN/TC 153

"Machinery intended for use with foodstuffs and feed", the secretariat of which is held by DIN

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2010, and conflicting national standards shall be withdrawn at the latest June 2010

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights This document includes Amendment 1 approved by CEN on 24 October 2009

This document supersedes EN 1673:2000

The start and finish of text introduced or altered by amendment is indicated in the text by tags

Introduction

!This European Standard is a type C standard as stated in EN ISO 12100

The machinery concerned and the extend to which hazards, hazardous situations and events are covered are indicated in the scope of this European Standard

When provisions of this type C standard are different from those which are stated in type A or B standards, the provisions of this type C standard take precedence over the provisions of the other standards, for machines that have been designed and built according to the provisions of this type C standard."

These ovens are used in the food industry and shops (bakeries, pastry-making, etc.) for the batch baking of foodstuffs containing flour, water and other additives This standard applies to ovens used only for food products except for those containing volatile flammable ingredients

The control of the humidity of the air in the baking chamber is by the production and introduction of steam around normal atmospheric pressure

The following machines are excluded:

 experimental and testing machines under development by the manufacturer;

Noise is not considered to be a significant hazard This does not mean that the manufacturer is absolved from reducing noise and making a noise declaration Therefore a noise test code is given in Annex B."

The hazards from the use of gaseous fuel by gas appliances are not covered by this standard

!This standard is not applicable to rotary rack ovens which are manufactured before the date of its publication as EN."

2 ! ! Normative references

The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

EN 294:1992, Safety of machinery — Safety distances to prevent danger zones being reached by the upper

limbs

EN 614-1:2006, Safety of machinery — Ergonomic design principles — Part 1: Terminology and general

principles

EN 953:1997, Safety of machinery - Guards - General requirements for the design and construction of fixed

and movable guards

EN 954-1:1996, Safety of machinery — Safety related parts of control systems — Part 1: General principles

for design

EN 1088:1995, Safety of machinery — Interlocking devices associated with guards — Principles for design

and selection

EN 1672-2:2005, Food processing machinery — Basic concepts — Part 2: Hygiene requirements

EN 60204-1:2006, Safety of machinery — Electrical equipment of machines — Part 1: General requirements

EN ISO 3743-1:1995, Acoustics — Determination of sound levels of noise sources — Engineering methods

for small, movable sources in reverberant fields — Part 1: Comparison method for hard-walled test rooms (ISO 3743-1:1994)

EN ISO 3744:1995, Acoustics — Determination of sound power levels of noise sources using sound pressure

— Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994)

EN ISO 4287:1998, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms,

definitions and surface texture parameters (ISO 4287:1997)

EN ISO 4871:1996, Acoustics — Declaration and verification of noise emission values of machinery and

equipment (ISO 4871:1996)

EN ISO 11201:1995, Acoustics — Noise emitted by machinery and equipment — Measurement of emission

sound pressure levels at a work station and at other specified positions — Engineering method in an essentially free field over a reflecting plane (ISO 11201:1995)

EN ISO 11688-1:1998, Acoustics — Recommended practice for the design of low-noise machinery and

equipment — Part 1: Planning (ISO/TR 11688-1:1995)

EN ISO 12001:1996, Acoustics — Noise emitted by machinery and equipment — Rules for the drafting and

presentation of a noise test code (ISO 12001:1996)

EN ISO 12100-1:2003, Safety of machinery — Basic concepts, general principles for design — Part 1: Basic

terminology, methodology (ISO 12100-1:2003)

EN ISO 12100-2:2003, Safety of machinery — Basic concepts, general principles for design — Part 2:

Technical principles (ISO 12100-2:2003)

EN ISO 13732-1:2008, Ergonomics of the thermal environment — Methods for the assessment of human

responses to contact with surfaces — Part 1: Hot surfaces (ISO 13732-1:2006)

EN ISO 13849-1:2008, Safety of machinery — Safety related parts of control systems — Part 1: General

principles for design (ISO 13849-1:2006)"

3 Description

A rotary rack oven usually consists of the following parts (see figure.1):

a) container built with insulated panels;

b) baking chamber with access door;

c) heat production unit;

d) hot air circulation system;

e) rack and trays;

f) drive unit for rack rotation;

j) miscellaneous devices (e.g combustion product flue where gas or fuel fired);

k) device to hold the removable rotary racks

Figure 1 — Parts of a rotary rack oven

4 ! ! List of significant hazards

4.1 General

This clause contains all the significant hazards, hazardous situations and events, as far as they are dealt with

in this Standard, identified by risk assessment as significant for this type of machinery, and which require action to eliminate or reduce the risk."

The example in figure 2 shows the danger zones:

Zone 1: rotation of the rack inside the oven

hazards of shearing, trapping, impact;

Zone 2: drive mechanism

hazards of shearing, trapping;

Zone 3: space between the rack and the door frame

hazards of shearing, trapping, impact;

All zones: sharp corners and edges on touchable parts hazards of cutting

There is also a hazard relating to loss of stability of the trays and of the rack during rotation and on entering the baking chamber

4.3 Electrical hazards

Hazard of electric shock from direct or indirect contact with live components

Hazard of external influences on electrical equipment (e.g cleaning with water)

4.4 Thermal hazards

4.4.1 Escape of steam from the baking chamber on opening the door creates a hazard of burns

4.4.2 High temperature of external parts and hand operated components creates a hazard of burns

4.5 Explosion and fire hazards

4.5.1 Overpressure of steam inside the baking chamber creates a hazard of explosion

4.5.1.1 The use in the oven of combustible substances (for example sugar) can create a hazard of fire

4.5.1.2 Improper operation of control and adjustment components of the combustion equipment can create

a hazard of overheating of the oven and of fire

4.6 Hazard from being trapped inside

Hazard of burns and suffocation

4.7 Hazard generated by neglecting hygienic design principles

The neglecting of hygienic principles can create unacceptable modification of foodstuff and therefore a risk to human health, i.e through physical, chemical or microbial pollution

4.8 Hazards generated by neglecting ergonomic principles

During loading and unloading racks, cleaning and maintenance, there is a risk of injury or chronic damage to the body resulting from awkward body postures, heavy lifting, pushing and pulling

5 ! ! Safety and hygiene requirements and/or protective measures" "

5.1 ! ! General

Machinery shall comply with the safety requirements and/or protective measures of this clause

In addition, the machine shall be designed according to the principles of EN ISO 12100-2 for relevant but not significant hazards, which are not dealt with by this document

For hazards which are to be reduced by the application of the type B-standards such as EN 294, EN 614-1,

The safety related devices and their interface with the control systems shall meet at least category 1 of 6.2.2

of EN 954-1:1996 or present at least a performance level c defined in accordance with EN ISO 13849-1:2006 When fixed guards, or parts of the machine acting as such, are not permanently fixed e g by welding, their fixing systems shall remain attached to the guards or to the machinery when the guards are removed."

5.2 Mechanical hazards

5.2.1 !!Zone 1: Rotation of the rack inside the oven""

Where reference is made to interlocking devices throughout clause 5, they shall comply with clause 4.3.1 and clauses 5 and 6 of EN 1088:1995

Safety related control systems be to category 1 of EN 954-1:1996

!deleted text"

If the force required to stop the rotating rack is greater than or equal to 150 N, access to the baking chamber, while the rack is rotating, shall be prevented by an interlocking door (e.g using a rotary cam operated switch) Opening the door shall cause the rack to stop within 3 s Any operation which requires the rack to rotate under power, with the door open, shall be controlled by a hold-to-run control

5.2.3 Zone 2: Drive mechanism

If the sum of distances from the floor to danger point is less than 2,5 m, access to the external transmission shall be prevented by fixed guards in accordance with EN 953 : 1997

5.2.4 Zone 3: Space between the rack and the door frame

Means shall be provided to prevent hand injury when moving the rack in and out of the oven

Since the movement is manual and controlled by the operator, this may be achieved by providing a clearance

of 50 mm between the rack and the sides of the door frame

5.2.5 All zones - External surfaces and edges

!External rough surfaces and sharp edges on the oven shall be avoided in accordance with 4.2.1 of

EN ISO 12100-2:2003."

5.2.6 Loss of stability

5.2.6.1 Stability of the rack during the rotation

To prevent overturning of the rack during rotation and engagement/disengagement of the drive, one of the solutions shown as examples in figure 3 may be adopted Other technical solutions giving the same level of safety level are also permitted

In figure 3 b), the rack is manually pushed onto the rotation system lifting hook and then lifted off the ground The rack shall remain stable during rotation on the oven floor This may be achieved by a coupling at its axis

of rotation or by other means

Figure 3 a) — Rotating platform with ramp Figure 3 b) — Rotating system lift hook

The rack is manually pushed onto the rotating

platform

The rack is manually engaged and lifted onto the rotating system

Figure 3 c) — Automatic lifting unit

The rack is manually engaged onto the lifting system and automatically lifted when the door is closed

Figure 3 - Examples of rotary rack coupling systems

5.2.6.2 Stability of the rack entering the baking chamber

To prevent the rack overturning on entering the oven a ramp or other suitable device shall be provided if the difference in level exceeds 10 mm

5.2.6.3 Stability of the rack

The rack shall be stable when titled 10° from the horizontal plane in the most unfavourable position

5.2.6.4 Stability of the trays

When trays are supplied by the manufacturer, the design shall prevent accidental displacement of the trays, especially during loading and unloading of the oven If the slope of the floor is over 10 degrees, trays shall be secured in the rack When trays are not supplied by the manufacturers, these requirements shall be described

in the instruction handbook

5.3 ! ! Electrical hazards

5.3.1 General

The electrical equipment shall comply with EN 60204-1:2006

Electrical equipment, for example switches, that may be exposed to water, e g during cleaning, shall be protected to an appropriate IP rating according to EN 60529 and EN 60204-1

5.3.2 Safety requirements related to electromagnetic phenomena

The machines shall have sufficient immunity to electromagnetic disturbances to enable them to operate safely

as intended and not fail to danger when exposed to the levels and types of disturbances intended by the manufacturer

The manufacturer of the machines shall design, install and wire the equipment and sub-assemblies taking into account the recommendations of the suppliers of these sub-assemblies

5.3.3 Protection against electric shock

The electrical equipment shall comply with Clause 6 of EN 60204-1:2006

5.3.4 Power circuits

Devices for detection and interruption of over-current shall be applied to each live conductor in compliance with 7.2.3 of EN 60204-1:2006 In case of single phase machines, no such device is required for the earthed neutral conductor

5.3.5 Protection against earth faults in control circuits

For machinery supplied from a single-phase conductor and an earthed neutral conductor, there is no requirement for double pole interruption of the control circuit The single pole interruption shall be in the phase conductor (see 9.4.3.1 of EN 60204-1:2006)

5.3.6 Emergency stop

Machines shall be fitted with at least one emergency stop (see 10.7 of EN 60204-1:2006), as far as the risk assessment carried out by the manufacturer doesn't allow to establish that such a device would not reduce the stopping time, or would not enable the special measures, required to deal with the risk, to be taken

In general no emergency stop is required for rotary rack ovens In this case particular attention shall be given

to the accessibility of the normal OFF switch from the operator position

Escape of steam shall be prevented by suitable means, for example by an extractor when opening the door

A special warning on an indelible plate, that cannot be removed, shall be affixed to the front of the door stating that "the door shall be opened with care"

When opening the door of the baking chamber:

 the extractor shall be switched on automatically;

 the water feeding device to produce steam, if it is automatic, shall be switched off automatically;

 the air circulation inside the oven shall be switched off automatically

5.4.2 Hot external surfaces

To prevent injury from hot external surfaces, the oven shall be provided with insulation so that the temperature

of front metal surfaces does not exceed the 70 °C according to !EN ISO 13732-1:2006", 10 minutes after the door is closed

5.4.3 Manual controls

External crank handles, handles and similar manual controls which in ordinary use are held in the hand for up

to 3 s, shall not exceed the temperature limit value of 65 °C for an uncoated metal handle

For other materials, see !EN ISO 13732-1:2006"

5.5 Fire hazards due to overheating

5.5.1 To prevent overheating of the oven, it shall be controlled by a temperature regulator and by an

independent thermostat which prevents the temperature in the baking chamber exceeding 400 °C

5.5.2 To prevent overpressure inside the baking chamber, a device shall be provided to operate the steam

discharge valves (flaps) before opening the door Such a pressure relief valve shall vent to a safe area e.g above the oven

5.6 Hazard from being trapped inside

To prevent any person becoming trapped inside the oven, any door of height greater than 80 cm, shall be provided with an opening device on the inside face which require a force no greater than 125 N to operate it The door shall be provided with a window with transparent material to allow vision inside the oven

When using glass or plastic these shall withstand a temperature of at least 300 °C

The splash area is as follows:

 the inside face of the access door;

 the opening handles of the door;

 the rack

5.7.4 Non food area

The rest of the oven, including the wheels or the castors of the rack, does not come into contact with the food

Food area

Splash area

Non food area

Figure 4 a) Figure 4 b)

Figure 4 — Hygiene areas

Insulation material shall be enclosed by steel plates or other material of similar strength which prevent insects and vermin from entering

5.8 Hazards generated by neglecting ergonomic principles

Awkward body postures during operation, cleaning and maintenance shall be avoided by design

Pushing and pulling with excessive effort shall be avoided e.g by use of low-friction castor wheels or by the design of the rack coupling mechanism

The force required to hook and to unhook the rack shall be no greater than 150 N

Object with a mass of more than 100 kg shall not be manually handled To avoid this, for example, an automatic lifting unit may be used

Control devices shall be positioned to allow the operator to reach them as stated in annex A of !EN 1:2006"

614-6 Verification of the safety and hygiene requirements and/or measures

!This clause contains the methods of testing for the presence and adequacy of the safety requirements stated in Clause 5 All safety measures of Clause 5 contain self-evidence criteria of acceptance

Table 1

Relevant

subclause Method of verification

5.2.1 By operation of the hold-to-run control and by measurement of time and force

5.2.2

5.2.3 By measurement and visual inspection

5.2.4 By visual inspection

5.2.5 By functional test

5.2.5.3 By test : when titled 10°, the rack shall return to upright position

5.3 Verification shall be in accordance with Clause 18 of EN 60204-1:2006

5.4.1 Functional test and visual inspection

5.8 By measurement of the forces

By inspection of the visibility of the indications, buttons

The instruction handbook shall meet the requirements of 6.5 of EN ISO 12100-2:2003

In particular, the instruction handbook shall provide:

 the provisions for handling, transportation, storage, installation and starting up;

 the provisions for cleaning: the cleaning products to be used, the recommended implements, the procedures and frequency, any necessary warning (for example, the cleaning shall be done once the machine is stopped, using a brush, a plastic scraper, a duster, a vaccuum cleaner, … Metallic implements are not recommended);

 information warning the users about the risk of burns by contact or from steam when opening the door;

 a warning about the risk when cooking flammable food;

 the limits that shall be respected and the measures to be taken for ensuring stability during use, transportation, assembly, dismantling when out of service, testing or foreseeable breakdowns;

 the operating method to be followed in the event of accident or breakdown; if a blockage is likely to occur, the operating method to be followed so as to enable the equipment to be safely unblocked;

 the specifications of the spare parts to be used, when these affect the health and safety of operators;

 if need be: the description of the cleaning, adjustment and maintenance operations to be carried out by the user and the preventive maintenance measures to be observed;

 instructions to isolate the machine in a safe condition in the event of interventions such as repair or maintenance (isolation from energy supply of all nature, locking of the disconnecting device, neutralising residual energy, testing);

 in the case of machinery capable of being plugged into an electricity supply: information warning the user that he shall be able to check that the plug remains visible from any of the points to which he has access;

 the instruction handbook (and any sales literature describing the performances of the machine) shall contain the following information on airborne noise emissions, determined and declared in accordance with Annex B of this European Standard:

 the A-weighted emission sound pressure level at workstations, where this exceeds 70 dB(A); where this level does not exceed 70 dB(A), this fact shall be indicated,

 the peak C-weighted instantaneous sound pressure value at workstations, where this exceeds 63 Pa (130 dB in relation to 20 µPa),

 the A-weighted sound power level emitted by the machinery, where the A-weighted emission sound pressure level at workstations exceeds 80 dB(A)

Whenever sound emission values are indicated the uncertainties "K" surrounding these values shall be

specified The operating conditions of the machinery during measurement and the measuring methods used shall be described

7.3 Marking

The minimum marking shall include:

 the business name and full address of the manufacturer and, where applicable, his authorised representative;

 mandatory marking1);

 designation of series or type;

 designation of the machinery;

 serial number if any;

 rating information (mandatory for electrical products: voltage, frequency, power, …)

Annex A

(normative)

Principles of design to ensure the cleanability of rotary rack ovens

A.1 ! Terms and definitions

For the purpose of this Annex, the following definitions apply

A.2 Materials of construction

A.2.1 ! ! Type of materials

Materials of construction for food area shall comply with 5.2 of EN 1672-2:2005

Some materials (e g plastics) shall be the subject to overall or specific migration tests

NOTE European Directives give the list of materials in contact with food and foods intended for human consumption (see also CEN/TR 15623) Materials not mentioned in the European Directives are accepted as long as food compatibility

is proven."

A.2.2 Surface conditions

The surface finish of materials used on surfaces shall permit easy cleaning under satisfactory conditions The roughness values (Rz) according to !EN ISO 4287:1998" shall comply with the values given in tables A.1 and A.2

!deleted text"

!Table A.1 — Surface conditions for food area

Values in micrometres

Technique of construction Roughness (Rz )

— paint (test reservation)

— plastics (test reservation)

Technique of construction Roughness (Rz )

A.3.1.1 Connections of internal surfaces for food area

Two surfaces shall be connected according to:

 rounded edge having a radius greater than a curve of minimum radius (r1) of 3 mm obtained by:

 machining (cutting into material mass);

 bending the sheet metal (bending and forming);

 design (in moulds, foundry patterns, injection and blasting ) (see figure A.1.1)

(1) Food area

Figure A.1.1

(1) Food area

Figure A.1.2

(1) Food area

Figure A.1.3

Three surfaces shall be connected:

 by using rounded edges, with two rounded edges having a radius greater than or equal to 3 mm and the third having a radius greater than or equal to 7 mm;

 by angles of 135° (α1) so that the dimension (l1) between two bends is then equal to or greater than 7 mm (see figure A.1.4)

(1) Food area

Figure A.1.4

A.3.1.2 Connections of internal surfaces for splash area